The Seiko 8420-7740 is a watch model based on the 8420 movement.
Parts List
| K03N36SN01 | crystal |
| 26M08EE1 | crown |
| 0C150BA12 | case back gasket |
| 86581100 | crystal gasket |
| 86581120 | crystal gasket |
| WI167 | others - other band |
Caliber 8420
Seiko 8420-7740 Watch Guide